Welded metal and welded structure

Abstract

This welded metal contains C, Si, Mn, Ni, Cr, Mo, Ti, B, O, N and Nb+V in specific amounts, respectively, with the balance being made up of Fe and unavoidable impurities. In this welded metal, carbides having circle-equivalent diameters of less than 0.40 μm have an average circle-equivalent diameter of 0.10 μm or more, and intergranular carbides having circle-equivalent diameters of 0.40 μm or more have an average circle-equivalent diameter of 0.75 μm or less.

1 . A weld metal, comprising:
 C: 0.02 to 0.08 mass %;   Si: 0.10 to 0.30 mass %;   Mn: 1.20 to 2.0 mass %;   Ni: 0.50 to 3.00 mass %;   Cr: 0 to 0.70 mass %;   Mo: 0.10 to 0.70 mass %;   Ti: 0.04 to 0.08 mass %;   B: 0.0010 to 0.0050 mass %;   O: 0.030 to 0.100 mass %;   N: more than 0 mass % and 0.015 mass % or less;   Nb+V: 0.008 to 0.05 mass %; and Fe,   wherein   an average equivalent circular diameter of carbides each having an equivalent circular diameter of less than 0.40 μm is 0.10 μm or more, and   an average equivalent circular diameter of carbides present at grain boundaries and each having an equivalent circular diameter of 0.40 μm or more is 0.75 μm or less.   
     
     
         2 . The weld metal according to  claim 1 , further comprising: at least one component selected from the group consisting of:
 Cu: more than 0 mass % and 1.0 mass % or less;   Co: more than 0 mass % and 1.0 mass % or less; and   Al: more than 0 mass % and 0.030 mass % or less.   
     
     
         3 . A welded structure, comprising: the weld metal according to  claim 1 . 
     
     
         4 . A welded structure, comprising: the weld metal according to  claim 2 .